Magnetic switching circuit



Nov. 5, 1957 R. STUART-WILLIAMS EI 'AL R 7 MAGNETIC SWITCHING CIRCUIT IOriginal Filed Aug. 9. 1954 INVENTORS BYM/L 7'0/I/ fidiA/Eff' P0455 0?men ae 2672720 4:33 MAGNETIC SWITQHINGA CIRCUIT 7 Claims. (C l;3117-1-88). t

Matter flfilfi d t he y. h a kctsl J flppea vstintthet n p t nt P t f msorned? of. p cation; matter printed initajlics" indicgtes t'hf additlo ht ii mi n re ates fiotswitching, circuits and, more pa rt cuierly is animproved switching circuit bf the t'yfi'e" employing rhagne'tic cores. 7

The employmentotjfiignetic cores in a switching-s circuit-arrangement isdes c ribed'in- 31in article in Iii-r1 Rzyehmen in the RCA-Review forIiine 1'952, eniitl d statiqMagnetie Matrix Men1or;y' and Switching"Circuits." Also, the employment of; magnetic core dlifliiiKhili heendescribed in an article-by A'n Walng in; the Proceed lugs of the IRB forApril -1951', entitled Migne'tic Del ily Line Storage. i i

The megnetic switchesas described by Rajchmanare useful in driving themagnetic cores of a memdiy. t Th' value of these switches is that thenumber of lines which need be switched in order to write-into or readfrom a large array of mz gnetic cores in :i rnemory is considerahl-yj.reduced. The switches described heretofore have-heed of the typeinWhich-a substantially rndom access fora switching purposes is enabled.The address Of each switch core? which .represents the iaddresstof a.des'ired colt urnn..or. row must be established .i'nthetdriving. tubesused to .econtrol the switch.- This-,meohanisnn is .clea jyLeii-splainedjinttheflarticlet byRajchman. wheretsequeritialt i or. ,cyclicswitching for operationoflatmagnetic vmemone oriother device isudesired,'.the ,empl oyment of the, switch, shown ibyrtRajchman ,would require.:establ-ishmentsofteach' address, in sequence tforedriving purposesThisdeadsz to:v a complexity; of electronic; appzu-atusvandiassociatedequipe meat. 7

A; objectmhihe iptesent tinvem en ..is tqnprnvideia imple shif ng sitehiwh h per its; eq en al; operati n, withza min mum pftext rnal sl ctQniQ apnaremsn V Aifurthcr biect. i.;' pres nt-ti venti nsisit he pmesion 5; s iftin t w whi hzi m tetrel ahl nt ne mtism t n th semadqthereqfiqrei-i ill'. rt1. r= p zi ct, pfime imes ilttt sentieas y 4 m uhstimiqnr frma ie ytmes.- r qqe iee :thggegf .i per p med b i -lqe rpn e, qupm n i 1 1' .1. wi h s mqr. ie a etaad r ete t eexmqneve perate t tntthet ev' lywkll tit-t Thes t ncln ur hqnt .stt s f h PIQ BQ Y BQQW chievd.fine-t nt. mbedimeme he i tt l qe wl m Q magnetic cores are provided.All the i cqglge iq 11 Q1;- mnsare nit i l t au reteslii s Qmlit eatstlpt-t n e zr qret ntthe s wel ql mvew fi k n et mated at.the p qsitetolerit t A ifitsmP t lh first-3nds econ n lum t =e 9 4 t' war aidfitht-,PQlQIiFYH WP.imy etween-vl sset qlumns.,Fh t '.9wi h te t sot-s ev ssfihs PH 299??? ee qipe m Pa ns eis sxi f eta qttrq ett hsatte finkhemUnited States Patene C) Re. 24,387 Reissued Nov. 5, 1957 4 Nee la e leejees fli P' l/ 'n tiongi l gohje'cts and advantages thstood'frg'iiiitheifoilowingfieseription whe ne't'gtibri uie'acj Figure"1 sh 6v'v's;'ai-i the shifting switch; Figure 2 shows anotherembodiment of the shitting. swi te'li whereiiij when desired, thesh'ift'is pfeventedfizindl" Figure 3 lsho'w's 'a third embodiment of theshift fig: switch 'wher'ein, when desired," a "shift can be riiade''fbrg" weird; backward, or the' shiftprevented. v i Referring now toFigure I, there is shown an erhbodi ment of the invention wherein asequential switcli oper'ation'may-be achievedL Three coluhinsof 'cores'10, 20} 30 hre amp-loved with the cores Not the second columri'preferably beihg larger. than thetcoresf 10, .30 of-the first or thirdcolumnsl InCorderYto more easilyv explainwthc invention, Iet itlieunderstood that :whn Ta'coreis'tdriven. tdisatui'iitioniat onejmlairity,thisTwill be desi'gnated'as the' Rxficondition' of the core; The othersturzitiontcon; d-it'iontwilltbel designatedias N. a; The scoresemployed are preferably. those. havingtsub-e stantiallygrectaiagnla'rhysteresis-vcharacteristics; It is; known that.;when a; drivii1g. pulseisappliedtoj a ,core. having characteristicslofi thisfnat'ureand the,coreisflriven; fon example, from P .-to, ,N-, a coil: whichishinductiyely coupledttotthat'core twill-have a; ,voltage. inducedtherein-v; The duration tof. ,thevinducedsvol e ,dependstlupqn the;turnc ver. time .of thencore. This is ,nonanlms entan ous evcng lvut.,doves persist for, a perioiwhichti measurab e; and whiclgrexists for.intervals. Lonv l ep de t .o i tmicmn secon s;

g rding e: wi ehzt hewn i Figure t tbeia zi kume c fle e hei wbe t s-PP?- i i 9" ig eiimth tse qnsl@QlWEE B E QE than 6 mbe drive on;the,,assvqciatfidt. l'qi hi s lt blum i tends to make .Ihati core stay inthe, cong1iti o n A P-drive coil 22 isinductivelyeoupled tqallithetsqmst in the second andfirst columnsin series. A P-sdriveris;

3 applied to this coil from a source 24 so that the current pulse usedfor driving is first applied at the core 20" in the second column. Dueto the delay line elfects of the cores and their coupling, the cores 20,20', 20" in the second column begin to turn over to P before the drivingpulse reaches the cores 10, 10" in the first column. In View of this,all the cores in the second column apply inhibiting currents to thecores in the first columnthat is, all except the core 10 which isalready in P. These inhibiting elfects prevent the P drive from the coil22 on the first column of cores from turning these cores to P except theone core 10 which does not receive any inhibiting effect. This core isturned over from condition N to condition P with the result that anoutput voltage is induced in its output coil 12. It should be noted thatat this time all the cores in the second column are in condition P andonly one core 10 in the first column is in condition P. The remainingcores 10, 10 in the first column are in condition N.

The cores in the second column are each also coupled to associated coresin the third column by a coil 32, a series rectifier 34, a resistor 36,and a shunt rectifier 38 in a -manner to drive a third column core fromN to P whenever an associated second column core is also so driven. Thusall the cores in the third column are driven to condition P except theone 30 connected to the core 20 in the second column which was in P whenthe switching cycle was commenced. This third column core 30 remains incondition N. An N-drive coil 40 is coupled to all the cores in the firstand third columns in serial fashion. An N drive from a source 42 isapplied to the N drive coilwhich results in resetting the switched core10 in the first column to N and all the cores in the third column notalready in N to N.

. It will he noted that the cores in the third column are allrespectively coupled to a second column core next to the one from whichthey receive a drive. This coupling also employs a coil 46, a seriesrectifier 48, a series re- Sistor 50, and a shunt rectifier 52 in amanner to permit a turned-over third column core (going from P to N) toapply an N drive to the second column core. Thus all the second columncores are reset to N except the core 20' next to the one which was at Pat the beginning of the switching cycle. The switch is now in conditionfor the next switching cycle at which time the only output core to beturned over will be the one 10' next to the one that was turned over atthe first switching cycle. Thus, by the simple application of first a Pdrive and then an N drive, the shifting switch is made to operate insequence and complex addressing circuitry is eliminated. The rectifiersand resistors employed in each of the coupling means are connected toinsure that the drives are applied between cores in the directionsstated previously and are not reciprocal when the core which hasreceived the drive is driven back to its initial condition by the Ndrive.

Two switches of the type described in Figure 1 may be employed tooperate a core plane made of magnetic cores arrayed in columns and rows.One of the switches can be employed to drive column cores and the othercan be employed to drive row cores. The switches are made endless-thatis, the last core 30" in the third column is connected to drive thefirst core in the second column 20. Thus cyclic operation is insured.Furthermore, the switch may be made any desired size.

Reference is now made to Figure 2 of the drawing. Therein is shownapparatus for stopping the shifting operation of the switch andpermitting the switch drive to come from the same core as long as it isdesired. This is achieved by employing a fourth column of cores 60, 60,60". The first three columns of cores are interconnected in the samemanner as described previously. The fourth column of cores is employedas follows. Each core 60 of the fourth column is coupled to anassociated core 20 in the second column by a coil 62 in a manner suchthat whenever the second column core is driven the associated fourthcolumn core is likewise driven, and vice versa. There is also providedan inhibit coil 64 driven by a tube 66 which is coupled to all the coresin the third column and another inhibit coil 68 driven by a tube 70which is coupled to all the cores in the fourth column. At the start ofa cycle, all the cores 60, 60, 60" in the fourth column are at N.

If it is desired to achieve an advancing pulse action, then the fourthcolumn cores are inhibited by applying a pulse from an advancing pulsesource 72 to the tube 70 driving the fourth column inhibit coil 68. Theinhibit coil is maintained excited until the cycle of operation isfinished. If it is desired to achieve a holding switching action, thatis, no advance in the switching of the cores in the first column, thenthe inhibiting coil 64, coupled to the cores in the third column, isexcited by the tube 66 to which it is connected and the hold pulsesource 74 maintains this tube excited for the duration of the holdingcycle. The N-drive coil 40, which in the embodiment shown in Figure 1was coupled to all the cores in the first and third column, now iscoupled to all the cores in the first column, and, in addition, throughtwo switching tubes 80, 82 may connect in series with an N-drive coil86, 88 in either the third column or the fourth column through the oneof two switching tubes which is selected. By applying a pulse from aselect advance source to the grid of one of the switching tubes 80, theN-drive coil through the first and third core columns is excited andoperation occurs exactly as was described for Figure 1.

Let us consider the operation of the switch for a holding operation. Theoperation of a switch for an advancing operation will not be describedfor the reason that during this operation the cores in the fourth columnare inhibited against operation and, therefore, play no part. Instead,the condition will be considered when a hold pulse is applied to inhibitthe operation of the cores in the thirdcolumn. As previously describedinitially, all the cores in the first, second, and fourth column are atN except one core 20 in the second column. A P drive is applied and, asbefore, all the cores in the second column that are not already in P aredriven to P, thus inhibiting the cores in the first column. The onlycore in the first column that is driven to P will be the one 10 which isnot inhibited. As a result of this P drive on the second column, all thecores in the fourth column will be driven to P except one core 60, whichis coupled to the core 20 in the second column which was in P to beginwith. Thus, when the N drive is applied by exciting from the select holdsource 92, the tube 82 which connects the N-drive coil of the firstcolumn 40 with the N-drive coil 88 of the fourth column all the cores inthe fourth column which are not already in N are driven to N, thusrestoring the cores in the second column back to N. This leaves the samesecond column core 20 which was at P at the beginning of the cycle stillat P. Accordingly, when the next shifting switch operation occurs, theswitch does not shift but the core 10 in the first column which turnedover to P previously again will turn over to P upon the second switchingoperation. Thus by applying the inhibit current to either the third orfourth column of cores and by exciting the proper N restore coil, theswitch can be made to advance or stand still for successive operations.

' the second column instead of the succeeding cores. An

inhibiting coil 102 and driver tube 104 and exciting pulse source 106 isrequired for this fifth column and also an- 5 other when): to:*selectingghehN sestese mildmass mg flitougtethetfifth column ofinor'cs.ewheneaniadyance Ai descriptionxof theooperation nfothetswitcimri numsisv exactlyfthet same asawaszdescrihedr'foraFigure; L.-l.The;ine:hibit-coilsw64, 68 servc fthetrpmpmesofmenmumgnheithirdnandifourth:bolumnstrfirom-nconsidcratiniiainitheeswitch opt-5: erationivThis timecmhe'matheicoresr 100 initheififttrico .2: umniare driven;frdm': l? tot Nysthey :restore :the cores pro-r: ce'di ngsthe. ones:iirorn:whichrtheyareceivecthirs'iP Tdrivdn .steadi nft-restoring'theacores: succeedingathecones from: which thoyfreceiventhein: Pkdriste7-38 ishuWminuFigure :1 .1 ,As' previouslyiindicated;thfilNil'BStdll'COihiE selectembw applyingoaselectingasignalatolahextgridaofotheatuher-AOSU'whicimconpleizithenNiFrestorercoilstiO "in :thsbfirt column: with: theN hestoreicoihllfla iuithrrv fifthacodummza Accordingly, a shiftingswitch haszbeen described herein? which? ioperatess in:isequencez'eitiient inr a fonwardrg omini ta reverse vdim'ctioinandzwvhich: icanualso bei operatedntorree peat'fanioutpunzfrom.uhcizsame corez'e.Theinovclt shiftingz switchpermitsicyclitiioperationtnsingilessiexpensiyeiappaei ratus thanusedfheretofore-z'r WeJclaim:

1.) Ar-magnetictcora shifiting swit'ctcicompnising 1a first} secondgrandthlid column: ofL-magneticscores, each-.efi said cores: being:substantiallwsamrabie iinueithemofiitwot.pos: larities;salluthei-coresini saidufir'stsand third columns' ands allibufion'e ofilthetcores insaidi'second O1UmH b6ing SlIb i stanthilly saturated-at: saidi'one ofsaidtwo polaritiesesaid oneecorez in: :saiditseeondz-icolurnnz*heing'substantially saturaxedlatusaid oth'eicofrisaid' two polarities'wmeans'tot apply a drive to saturation =att-said iothenepoianityrtm the-coresofi' saidifirstiand second :column'g-first means: responsive to the:changing gofmsaid cores: in said *seeonds' column to satu ration at saidother polata'ty to iinhibit' thie drive OIL-Said cores in said firstcolumn, second means responsive to the changing of said coresdn saidseeond column to saturation at said other polarity to drive said coresin said third column to saturation at said other polarity, means toapply a drive to said cores in said first and third columns tosaturation at said one polarity, and third means responsive to the coresin said third column changing toward saturation in said one polarity todrive succeeding cores in said second column to saturation at said onepolarity.

2. A magnetic-core shifting switch as recited in claim 1' wherein saidfirst means includes a plurality of coils a different one of whichinductively couples a difierent core in said second column to adifferent core in said first column and a unilateral impedance for eachcoil and connected in series therewith; wherein said second meansincludes a plurality of coils, a diflerent one of which inductivelycouples a diflFerent core in said second column to a diiferent core insaid third column, and a unilateral impedance for each coil andconnected in series therewith; wherein said third means includes aplurality of coils, a diiferent one of which inductively couples adifferent core in said third column to the core in said second columnsucceeding the second column core to which said third column core iscoupled by said second means, and a unilateral impedance for each coiland connected in series therewith.

3. A magnetic-core shifting switch as recited in claim 1 wherein saidmeans to drive said first and second core columns includes a coilinductively coupled to all the cores in said columns and said means todrive said first and third columns includes a coil inductively coupledto all the cores in said columns.

4. A magnetic-core shifting switch comprising a first, second, and thirdcolumn of magnetic cores, each of said c res b ngis bsta tiellyss tutalasta -wi h n; Qfia i Qt. p larities, all-dik re n stfi stt n hirmqlmiandsa'lhbutxone. of-.: c-. res, .'sai51; s qoasi c umn b i b nti llvaswr e said o e-9 s id twersql r said one core; in said. second columnheir g,sill;stialutrally saturated at said. .otl1e 1:;.of ',said.v two,polarities m H; toapnly a riverto altjthe. c resins idfi ste sl, columnstoward, :saturation .,at,, said othe r pf sard twg polarities, means:coupled between ,cach of,,the cotgesiin s i ssecondw l mn dfie r t 1a othe wai -t said firstcolumn-rtoinhibit s q, ores. ,i .saiatirsts l. Ipan i e to .l eofiqifiz i s di e tmd .s lumashsasina tousaturation at-sideo herp a itse h r b only coreiinasaidifirst column. c pled. t n idcsel se i said: second. column-21s :driven toward, ,saturation at said,otherspolarity, means1 .coupled .between eachg f, p intsaidmsecond .c la ia d t er nt Quest es tss. in-,-:Saidthird; column. to, drive; said,scores saturation, at... saidotheraofa-s id-iwo. .polarities,,;respgnsive ,to the, core, ,in said.. second, ,column, changing; to, :saturationat said ,other. polarity.,wher ehy.-,all,the,,co1tesi,in,,ai1.: col ntiflt fi ones up e at psaid-one .cqregin id. second lcolumn rare driventoward. saturation at said, other ofi saidutwo. polarities, ,mean toapply a ,drive to; saidfirst and third columns dflcores. to drive saidpores, toward, saturation, at,said onepqlarjty, andmeansso pled,between; each of tires-cores; in ,said ,third co1umn ,andl, ladifferent,one;.of,,the, cores- 'n said sc cond.colpmn othgr n. es ns-thr'i s. a ready., qunl is ts tita a .second, columnvcore ,towards saidone condition of saturatiomresponsive, touthercore ,in sa1 d,, thirdcolumn, changing-;-to said,. .one condition. whereby. all .jhepcqres;saidesecpndtcoluma e iyen .suh tatiii l i QWQ Q said one condition ofsaturation but the pnekcoupled totsaid third cclumnm oret hich washleft.ir id e condition v of saturation prion i :to, application pi}, adri,ve, from 1 said :means to, apply a drive, .tor'said first and thirdcolumns.

e f A sn i rco e iftin .sw shs ol mb a; filth, second,- and-, thirdcolurnn. v.of .jnagneti c, cores, agh, 'of i ,c i c ngqsubst ntiallya 11 w-fi th iih ifi w po ar i s pl t liue-ni rst-J das I tsq l egms aaeach-ioti-whichand tit x ouples-.3 dxfiexsnti nel' wreswf i lisondcolumniwithe iqsntmlnapfitlha cores of said first column, each ofsaidfirst means including a unilateral current flow means, a pluralityof second inductive coupling means each of which inductively couples aditTerent one of the cores of said second column with a different one ofthe cores of said third column, each of said second means including aunilateral current flow means, a plurality of third inductive couplingmeans each of which inductively couples a different one of the cores ofsaid third column with a different one of the cores of said secondcolumn other than the core to which each said third column core isalready coupled, each of said third means including a unilateral currentflow means, means to apply a drive to said second and first rows ofcores to drive said cores toward core saturation at one of said twopolarities, and means to apply a drive to said first and third rows ofcores to drive said cores toward core saturation at the other of saidtwo polarities] 6. A magnetic-core shifting switch as recited in claim 1wherein said unilateral current flow means in each of said first meansis connected to permit current flow from said core in said second columnto said core in said first column, said unilateral current flow means ineach of said second means is connected to permit current flow from saidcore in said second column to said core in said third column, and eachsaid unilateral current flow means in said third means is connected topermit current flow from said core in said third column to said core insaid second column.

7. A magnetic-core shifting switch comprising a first, second, third,and fourth column of magnetic cores, each 7 of said cores beingsubstantially saturable in either of two polarities, a plurality offirst inductive coupling means each of which inductively couples adifferent one of the cores of said second column with a diflerent one ofthe cores of said first column, each of said first means including aunilateral current flow means, a plurality of second inductive couplingmeans each of which inductively couples a different one of the cores ofsaid second column with a different one'of the cores of said thirdcolumn, each of said second means including a unilateral current flowmeans, a plurality of third inductive coupling means each of whichinductively couples a different one of the cores of said third columnwith a different one of the cores of said second column other than thecore to which each said third column core is already coupled, each ofsaid third means including a unilateral current fiow means, a pluralityof fourth inductive coupling means each of which inductively coupleseach of the cores in said second column with a different one of thecores in said fourth column, means to apply an inhibiting drive to saidfourth column of cores when an advancing switch operation is desired,means to apply an inhibiting drive to said third column of cores when noadvancing switch operation is desired, means to apply a drive to saidsecond and first rows of cores to drive said cores toward coresaturation at said one of said two polarities, means to apply a drive tosaid first and third rows of cores to drive said cores toward coresaturation at the other of said two polarities when it is desired toobtain an advancing switch operation, and means to apply a drive to saidfirst and fourth rows of cores to drive said cores toward coresaturation at the other of said two polarities when no advancing switchoperation is desired.

8. A magnetic-core shifting switch comprising a first, second, third,fourth, and fifth column of magnetic cores, each of said cores beingsubstantially saturable in either of two polarities, a plurality offirst inductive coupling mean-s each of which inductively couples adifferent one of the cores of said second column with a different one ofthe cores of said first column, each of said first means including aunilateral current flow means, a plurality of second inductive couplingmeans each of which in ductively couples a different one of the cores ofsaid second column with a different one of the cores of said thirdcolumn, each of said second means including a unilateral current flowmeans, a plurality of third inductive coupling means each of whichinductively couples a diifer ent one of the cores of said third columnwith a different one-of the cores of said second column other than thecore to whicheach said third column core is already coupled, each ofsaid third means including a unilateral current flow means, a pluralityof fourth inductive coupling means each of which inductively coupleseach of the cores in said second column with a different one of thecores in said fourth column, a plurality of fifth inductive couplingmeans each of which inductively couples each of the cores in said secondcolumn with a different one of the cores in said fifth column, each ofsaid fifth inductive coupling means including a unilateral current fiowmeans, a plurality of sixth inductive coupling means each of whichcouples inductively each of the cores in said fifth column with adilferent one of the cores in said second column which are located in anopposite direction to the cores to which said third means are coupled,means to apply an inhibiting drive to said fourth and fifth columns ofcores when an advancing switch'operation is desired, means to apply aninhibiting drive to said third and fourth columns of cores when areversing switch operation is desired, means to apply an inhibitingdrive to said third and fifth columns of cores when neither advancingnor retarding switch operation is required, means to apply a drive tosaid second and first columns of cores to drive said cores toward coresaturation at said one of said two polarities, means to apply a drive tosaid first and third rows of cores to drive said cores to coresaturation at said other of said two polarities when it is desired toobtain an advancing switch operation, means to apply a drive to saidfirst and fifth row of cores to drive said cores to saturation at saidother polarity when it is desired to obtain a reversing switchoperation, and means to apply a drive to said first and fourth row ofcores to drive said cores to saturation at said other polarity whenneither advancing nor reversing switch operation is desired.

No references cited.

